• Structural Monitoring and Maintenance
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• 제6권3호
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• pp.255-268
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• 2019

Civil infrastructures, such as bridges and tunnels are most important assets and their failure during service will have significant economic and social impact in any country. Behavior of a bridge can be evaluated only through actual monitoring/measurements of bridge members under the loads of interest. Theoretical analysis alone is not a good predictor of the ability of a bridge. In some cases, theoretical analyses can give less effect than actual since theoretical analyses do not consider the actual condition of the bridge, support conditions, level of corrosion and damage in members and connections etc. Hence actual measurements of bridge response should be considered in making decisions on structural integrity, especially in cases of high value bridges (large spans and major crossings). This paper describes in detail the experimental investigations carried out on an open web type steel railway bridge. Strain gages and displacement transducers were installed at critical locations and responses were measured during passage of locomotives. Stresses were evaluated and extrapolated to maximum design loading. The responses measured from the bridge were within the permissible limits. The methodology adopted shall be used for assessing the structural integrity of the bridge for the design loads.

• 항공우주시스템공학회지
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• 제16권1호
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• pp.81-85
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• 2022

본 연구에서 항공기 엔진의 공기흡입구 복합재 적용 구조 설계 및 해석 연구를 수행하였다. 본 연구에서 설계를 위해 대상 구조물의 구조 설계 요구조건 분석을 수행하였다. 구조 설계 하중은 압력 분포 하중과 가속도 조건을 적용하였다. 구조 설게 결과를 검증하기 위한 구조 안전성 평가를 위해 유한 요소 해석이 수행되었다. 구조 안전성 평가를 위해 응력 해석, 변형 해석, 좌굴 해석이 수행되었다. 최종 구조 안전성 검토를 통해 설계된 공기흡입구는 안전성을 확보한 것으로 확인되었다.

• 국제초고층학회논문집
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• 제12권2호
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• pp.145-152
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• 2023

Typical floor systems in contemporary tall buildings consist of reinforced concrete or composite metal deck over framing members and account for a majority of the structural weight of the building. The use of high-density materials, such as reinforced concrete and steel, increases the weight of floor systems, reducing the system's overall efficiency. With the introduction of high-performance materials, mainly mass timber products, and fiber-reinforced composites, in the construction industry, designers and engineers have multiple options to choose from when selecting structural materials. This paper discusses the application of mass timber and carbon fiber composites as structural materials in floor systems of tall buildings. The research focused on a comparative analysis of the structural system efficiency for five different design options for tall building floor systems. Finite Element Analysis (FEA) method was adopted to develop a simulation framework, and parametric structural models were simulated to evaluate the structural performance under specific loading conditions. Simulation results revealed the advantages of lightweight structural materials to improve system efficiency and reduce material consumption. The impact of mechanical properties of materials, loading conditions, and issues related to fire engineering and construction were briefly discussed, and future research topics were identified in conclusion.

• The Journal of Asian Finance, Economics and Business
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• 제9권1호
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• pp.13-24
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• 2022

The main goal of this study is to look at how South Korea can catch up to the rest of the world through policy-driven structural change and manufacturing revolutions. To achieve the objective, this study used annual data on real exports and real GDP from the World Development Indicator WDI of South Korea for the period 1960 to 2019. The study's goal is to use econometrics to detect this policy-driven structural change trend. Multiple nonlinear Granger causality test was used to accomplish this. The findings revealed structural breaks and nonlinearities in the dynamic link between South Korea's real GDP and real exports. Furthermore, results also show evidence of multiple structural breaks in South Korean data. South Korea's economic catch-up was the result of a constant reevaluation of industrial policies, readjustment, and structural change to constantly explore and utilize comparative advantage, realizing economies of scale at the global level, and reallocating and redistribution of resources towards productive sectors with high value-added output, according to econometric analysis. If South Korea would have not done this structural change this miracle to escape the middle-income trap would not have been possible. These findings support the descriptive evidence of structural change in favor of manufacturing revolutions and value addition industry development in South Korea.

• Structural Monitoring and Maintenance
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• 제10권2호
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• pp.133-154
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• 2023

Obscured structural members are mostly under-evaluated during condition assessment due to lack of visual inspection capability. Insufficient information about the integrity of these structural members poses a significant risk for public safety. Time domain reflectometry (TDR) is a novel approach in structural health monitoring (SHM). Ordinary coaxial cables "as is" without a major modification are not suitable for SHM with TDR. The objective of this study is to propose a practical and cost-effective modification approach to commercially available coaxial cables in order to use them as a "cable sensor" for damage detection with the TDR equipment for obscured structural members. The experimental validation and assessment of the proposed modification approach was achieved by conducting 3-point bending tests of the model piles as a representative obscured structural member. It can be noted that the RG59/U-6 and RG6/U-4 cable sensors expose higher strain sensitivity in comparison with non-modified "as is" versions of the cables used. As a result, the cable sensors have the capability of sensing both the presence and the location of a structural damage with a maximum aberration of 3 cm. Furthermore, the crack development can be monitored by the RG59/U-6 cable sensor with a simple calibration.

• 아태비즈니스연구
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• 제14권3호
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• pp.103-114
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• 2023

Purpose - The purpose of this study was to examine the relationship between organizational tenure, structural career plateau, and interpersonal deviant behavior for nurses. Moreover, this study also investigated moderating role of proactivity on the effect of organizational tenure on structural career plateau. Design/methodology/approach - This study utilized 448 nurses working at three different types of hospital. The Exploratory Factor Analysis (EFA) and the multiple regression analysis were conducted to verify the hypotheses. Findings - The results showed that organizational tenure is positively related to structural career plateau and structural career plateau is positively related to interpersonal deviant behavior. However, moderating effect of proactivity is not significant. Research implications or Originality - Nurses are critical to the competitiveness of hospital organizations considering the proportion of manpower and the role of nurses. One of the important factors that decrease the motivation of nurses is structural career plateau. This study analyzed the antecedent and consequence of structural career plateau. In addition, practical implications for resolving the problem of structural career plateau were provided.

• 한국전산구조공학회논문집
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• 제24권6호
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• pp.601-608
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• 2011

부유구조체의 설계를 위해서는 파랑하중하에서 부유구조체의 파랑운동 특성과 구조거동에 대한 평가가 요구된다. 부유구조체의 구조거동 평가에서는 파랑하중에 의한 파압분포가 반영되어야 하지만, hydrodynamic 해석모델과 구조해석 모델사이의 파압 연계가 어려워 정확한 구조거동 평가가 어려웠던 문제점이 있었다. 본 논문에서는 파랑하중하에서 대형 부유구조체의 정확한 구조거동 평가를 목적으로 파랑운동-구조거동 통합해석을 실시하였다. AQWA에 의한 hydrodynamic 해석을 바탕으로 부유구조체에 작용하는 파압 분포를 ANSYS Inc.에서 제공하는 Workbench 인터페이스를 이용하여 ANSYS의 구조해석 모델에 연계하였다. 연구결과 본 연구의 파랑운동-구조거동 통합해석은 파랑하중에 의해 부유구조체에 발생하는 파압분포를 구조해석 모델에 정확하게 반영할 수 있어 파랑하중에 의한 부유구조체의 구조거동을 정확하게 평가할 수 있는 것으로 나타났다. 또한, 상부 슬래브의 인장응력은 파랑 입사각 $0^{\circ}$의 경우에 가장 불리하고, 하부 슬래브의 인장응력은 파랑 입사각 $45^{\circ}$의 경우에 가장 불리한 것으로 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제23권5호
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• pp.96-103
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• 2019

중층 철근콘크리트 주거형 건물은 국내에서 많은 비중을 차하며, 이러한 건물의 시공단계에서 발생 될 수 있는 문제에 대한 구조성능 분석이 필요하다. 이를 위하여, 25층 규모의 중층 철근콘크리트 주거형 건물을 예제모델로 선정해 구조성능 분석을 진행하였다. 예제모델을 5층, 10층, 15층, 20층, 25층의 시공단계 모델과 설계가 완료된 완공단계 모델로 구분해 구조해석을 수행하였다. 완공단계와 시공단계 모델들에 대하여, 고유치해석, 횡력저항성능, 완공단계에서의 설계강도비와 시공단계에서의 설계강도비를 비교를 통한 단면성능 검토를 수행하였다. 검토 결과, 시공단계와 완공단계 모두 횡변위와 층간변위비에서 건축구조기준 제한을 초과하지 않았는 것을 확인하였고, 단면성능 검토에서는 벽체의 일부 데이터를 제외한 모든 부재에서 구조적 안전성을 확인하였다. 따라서, 중층 철근콘크리트 주거형 건물의 완공단계에서 구조적 안정성이 확보되면 시공단계에서도 구조적 안정성 학보가 이루어진다는 결론을 도출할 수 있었다.

• 한국전산구조공학회논문집
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• 제22권1호
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• pp.15-23
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• 2009

압축력에 강한 석조 홍예아치교의 경우 재료적 음력한계보다는 구조적 형상의 불안정성에 의해서 구조물이 붕괴된다. 이러한 특성을 고려하면, 석조 홍예아치교의 구조적 안정성 평가에는 구조물의 붕괴기구 형상에 초점을 둔 한계상태 해석이 보다 적합하다. 이 연구에서는 한계상태 해석법을 이용하여 건식법(dry construction)으로 축조된 우리나라 석조 홍예아치교의 구조적 거동을 살펴보고, 이 결과를 구조적 안정성 평가시스템 개발에 이용하고자 한다. 이 연구결과는 우리나라 석조 홍예아치교의 구조적 거동을 이해하는데 도움이 되며, 향후 문화재 유지관리 측면에서 공학적 판단기준을 주리라 기대한다.

• 대한조선학회논문집
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• 제53권4호
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• pp.336-342
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• 2016

H-CSR(Harmonized Common Structural Rules) integrating CSR-BC(Common Structural Rules for Bulk Carriers) and CSR-OT(Common Structural Rules for Double Hull Oil Tankers) came into effect in July of 2015, so that bulk carrier and double hull oil tanker should comply with this rules. So far, several studies for trend analysis of requirements of structure scantling based on H-CSR have been carried out briskly. However, those studies are rare to apply H-CSR in actual structural design of ships, especially bulk carriers. In this study, an automated system for compartment arrangement is used to search the design case that minimizes still water bending moment(S.W.B.M) in 38k bulk carrier designed by Far East Ship Design & Engineering Co. Ltd. Also, various structural design cases are considered by changing arrangement of structural members to reduce ship weight. The SeaTrust-Hullscan software developed by Korean Register is used to perform structural design of ships based on mother ship and proper design cases are selected by user. The DSA(Direct Strength Analysis) is performed to evaluate structural safety for the yielding and buckling analysis by using MSC Nastran software. The effect of weight reduction is verified by comparison of ship weight between mother ship and the selected design cases.